Metal working machine



METAL WORKING. MACHINE Filed April 22; 1952 2 Sheets-Sheet '1 INVENTORARmuRFHANsoN ATTORNEY Nov. 13, 1934. V A, F HANSON 1,980,584

METAL WORKING MACHINE Filed April 22, 1932 2 Sheets-Sheet 2 INVENTORARTHURFH AHSON ZWMM ATTORNEY Patented Nov. 13, 1934 METAL WORKINGMACHINE Arthur F. Hanson, Philadelphia,

Budd Wheel Company,

Pa., assignor to Philadelphia, Pa., a corporation of PennsylvaniaApplication April 22, 1932, Serial No. 606,774

10 Claims.

This invention relates to metal working machines and more particularlyto an actuating mechanism therefore having for its principal object theconstruction of a machine and mechanism which will enable very accuratecontrol of the die movement during the working operation, and which willallow a very large relative movement of the dies during the loading andunloading operations of the machine independently of the cam controllingsurface used during the working operation. Another object of myinvention is to construct a cam which will be relatively inexpensive tomake.

I attain the above desirable objects and'others incidental thereto byconstructing a metal working machine having in combination relativelymovable dies and actuating mechanism therefor including a cam arrangedtocontrol the die movement during the'welding operation and to receivethe follower in nested relation during the work charging and dischargingpart of the operations. V I

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope will be pointed out in the appended claims.

In the accompanying drawings wherein like ordinals representcorresponding parts in the various figures,

Fig. 1 is a side elevation of a machine made in accordance with theteachings of my invention.

Fig. 2 is a plan view of the same machine. I

Fig. Bis a skeleton view showing the relative parts of the cam mechanismand the follower means;

Fig. 4: is a section on the line 4--4 of Fig. 3.

Fig. 5 is a view taken from the right side of Fig. 3 looking to the leftshowing the control mechanism schematically associated with the cam andits follower.

Resulting from the construction herein disclosed I eliminate the need ofexpensive cams 5 and make the machine much more compact having theassociated operating parts requiring much less head room than would ofnecessity be required'with a machine using an ordinary cam of largesize.

In accordance with my invention I provide a metal working machine havinga general framework including a base 10, a plurality of supporting sidemembers 11 and an upper structure 12 generally housing and supportingthe operative ,parts of the machine. Mounted upon the base member 10 isthe lower stationary die member or electrode 13. The electricalconnections to this member are not shown as any suitable connection willserve the purposes of my ma.- chine. Upon brackets 14 suitably mountedupon the base member 10 and properly located with respect to the diesare a plurality of pneumatically operated mechanisms 15 controlling themembers 16 which are positioned between the individual work pieces,supporting them in separated relation by means of yielding resistance.This mechanism is covered by other patent applications and is onlyincidental to the present disclosure, consequently a further discussionthereof is deemed unnecessary. It will be apparent, however, that theseinstrumentalities are necessarily coordinated with the operations of thedies. vSlidably mounted in the guide-ways 17 of the vertical framemembers 11 is an upper platen 18 adapted to have secured to the lowerface thereof the upper die or electrode 19. The member 19 is necessarilyinsulated from the platen and connected to a proper source of power. Bymeans of the mechanism so far described it is obvious that relativemotion between the upper and lower dies may be obtained.

The primary raising and lowering operations of the platen 18 areobtained by means of a plurality of pneumatically operated mechanisms 20mounted at the top of the machine upon the cross structures 12.Interiorly of these cylinders are arranged pistons 21 connected by meansof rods 22 to the shoulders 23 upon the platen. The raising and loweringof the platen is attained through this mechanism by means of controlvalves and air-lines, not shown. Raising motion is attained byintroducing air in the lower part of the cylinder forcing the pistonsupward whereas lowering movement is accomlished by exhausting thecylinder. It is obvious that these same members may be used as a bufferor shock absorber to position the die in its lowered initial workingposition by merely retaining in the cylinders a sufficient quantity ofair to accomplish this result.

To accurately control the die movements during the loading and unloadingoperations of the machine as well as during the welding operationsadditional mechanism is required including a cam to be later described.This mechanism comprises essentially the cam 24 mounted upon the shaft25 which is secured to the upper frame member 12 by means of suitablebrackets 26. To accomplish the rotary motion of shaft 25 a source ofpower, for example, an electric motor 30 is used. The motor drives areducing gear located within the gear housing 27 by means of a chaindrive 28. The reducing gear is externally associated with the pinion 29meshing with the large gear wheel 31 upon the shaft 25. The drive to theshaft from the motor is through the chain drive 28, the gearreducingmechanism in the housing 27 to pinion 29 and thence through the largegear wheel 31. To accurately control this drive it it necessary to haveassociated with the driving motor an electro-magnetic brake mounted uponthe top of the machine and coacting with the motor by means of abrake'drum 32. This mechanism generally indicated at A is of the typecommonly used for this purpose.

The previously described parts of the machine and the operation thereofco-operate to enable the presently described cam mechanism to properlyfunction. Cam 24, as shown in Fig. 4, has a removable surface 33 whichis the active or controlling surface of the cam. The particularconstruction illustrated comprises a short circumferential portion 34generally considered the initial take-up to position the work parts justprecedent to beginning the flash. The remainder of the cam surface up tothe point 35 has a gradual increase in taper which allows the parts toapproach gradually continuously and in a pre-determined manner so as toburn away the adjacent surfaces preparatory to the push-up which occursat point 35 immediately before cutting off the power. The upper die 19is actuated by means of a follower member 38 including a roller 39adapted to engage the surface of the cam 33.

The cylindrical portion 36 of the cam has a slot 37, as shown, having adepth considerably in excess of the maximum cam radius and closelyapproximating in width the cylindrical diameter of the follower. I canraise the die 19 a relatively great vertical distance away from thelower die by allowing the follower means including the member 38carrying the roller 39 to nest within the slot during the inactiveperiod of the machine. loaded and the elemental parts have been placedbetween the dies, the pneumatic control means are caused to operate,lowering the die by means ofthe co-acting piston rods and platen intoposition. The follower is now positioned immediately below the campreparatory to the welding operation. In this position the machine maybe safely started and the welding operation begun. At the end of thesequence of motions obtained by the cam, the member 38 is again raisedwithin the slot 37 allowing the work to be removed. It is readilyapparent that by means of the cam herein described a very accuratewelding operation may be performed by means of the cam surface and avery large vertical movement of the die can be obtained due to thenesting relation of the follower within the slot.

To accomplish this same desirable result with ordinary construction itwould be necessary to have a cam of extremely large dimensions possiblyas much as four feet in diameter. It is obvious that such a cam would beextremely expensive.. The present construction allows a relativevertical movement of approximately 20 inches with a cam of possibly notmore than two feet in diameter.

At the right hand end of the shaft 25, as seen in Fig. 3, is a member 40suitable for carrying a plurality of contacting control elements 41After the machine has been and 42, visible in Fig. 5, for operating thevarious switches. The push button switch 43 is used to initiate therotary movement of the cam thru the motor 30, the circuit thereof beingcontinued after the hand operated initiation thereof by means of theswitch 44 which is freed from the eccentric member 41. The powerassociated with the dies for the flash welding is controlled by means ofsuitable switch 45 likewise associated with an eccentric cam member 42.

In the nature of safety measures operative during the action of thismachine, a switch 46 is connected by means of a roller and bell-crank 48and 49 for association with a member 50 mounted upon the ram 38. As longas the ram 38 is in its raised position the switch 46 cannot close. Thisswitch controls the main power source and consequently the machine mustremain inoperative as long as the switch is open. After the machine hasbeen loaded and the ram has been lowered, the switch 46 closes and themachine operation may thus be initiated. Should the machine beginoperation when some rigid structure is between the die faces, some partof the same would necessarily break. To avoid this danger a steel washer51 is mounted between two co-acting collars 52 and 53. When the loadexerted upon the washer exceeds the shearing stress of the member thisjoint gives way and the cam surfaces are not damaged. In this mannerrelatively inexpensive parts of the machine may be replaced without anypossible destruction of the expensive dies or cam surface. 1

My machine is readily adaptable for quantity production and thereinfinds its most acceptable use. The embodiment of the invention hereindescribed and illustrated has been selected for the purpose of clearlysetting forth the principles involved. It will be apparent, however,that the invention is susceptible of being modified to meet thedifferent conditions encountered in its use and I therefore aim to coverby the appended claims all modifications within the true spirit andscope of. this invention.

I claim as my invention:

1. In an electric flash welding machine, dies having a degree ofapproach toward and recession from each other measured by thosemovements required for proper functioning of the dies in carrying outthe welding operationper se, a cam arranged to control said die movementand having a peripheral contour designed to afford such movement only,and means carried by said cam butinclependent of the periphery thereofarranged to aiford a relative die movement from and toward each otherrelatively much greater than the said degree of movement required tocarry out the welding function per 2. A metal working machine having incombination, relatively movable dies and actuating mechanism thereforeincluding a cam arranged to control the die movement during the workingoperation and a slot in said cam arranged to' receive a follower innested relation during the work charging or discharging operations.

3. In a metal welding machine, the combination of relatively movablewelding dies, power means including a ram for supplyingpredeterminedpressure to a die during the welding operation and a camfor imparting working movement to said ram, control means operated bysaid ram in inactive position to prevent operation of the machine, ahand operated switch to' Initiate machine operation and a plurality ofswitches associated with said cam, one to continue machine operationafter the initiation thereof and one to control the welding circuit insynchronism with the die movement.

4. In an electric flash welding machine, dies having a degree ofapproach toward and recession from each other measured by thosemovements required for proper functioning of the dies in carrying outthe welding operation per se, a cam controlling this movement and havinga peripheral contour designed to afford such movement only, and meansincluding a slot independent of said periphery to afiord a relative diemovement from and toward each other relatively much greater than thesaid degree of movement required to carry out the welding function perse.

5. In a metal working machine, the combination of, relatively movabledies, a cam for imparting predetermined movement to said dies and havinga diametral slot, follower means arranged to transfer the cam motion toa die, and means arranged to position said follower means in operativerelation to the cam surface or nested interiorly of said slot.

6. In an electric flash welding machine, dies having a degree ofapproach toward and recession from each other measured by thosemovements required for proper functioning of the dies in carrying outthe welding operation per se, a cam controlling this movement having aperipheral contour designed to afford such movement only, and adiametral slot therein independent of said periphery arranged to afforda relative die movement from and toward each other relatively muchgreater than the said degree of movement required to carry out thewelding function per se.

7. A machine adapted to butt weld together the cross sectional parts ofmembers of hollow cross section, comprising relatively movable weldingdies, means arranged to position one of said dies into relative workingposition, means arranged to control the die movement during the workingoperation and independent means co-operative therewith arranged toprovide relatively much greater relative die movement than the degree ofdie movement requisite during the working operation.

8. A metal working machine having, in combination, relatively movabledies and actuating mechanism therefor including a cam arranged tocontrol the relative die movement during the metal working operation perse, a follower arranged to transfer the cam contour motion to said dies,said cam having a diametral slot of a depth at least so great as themaximum cam radius, and arranged to receive said follower in nestedrelation thereto during the work charging or discharging operations.

9. In a metal working machine, the combination of relatively movabledies, a cam for imparting pre-determined movement to said dies andhaving a diametral slot, follower means arranged to transfer said cammotion to said die, means arranged to position said follower inoperative relation to said cam surface or nested interiorly of saidslot, and means interconnecting said follower means and said die, andarranged to pre-determine the load transmitted through theintermediation of said follower means.

10. In a metal working machine having relatively movable dies, a camarranged to control said dies during a portion of their relativemovement, and means independent of the periphery of said cam providing arelative movement of said dies greater than the maximum radius of saidcam surface.

